Gday fellas
I recently inherited a 1993 toyota hilux 2.8 diesel 3l engine.
My granddad gave me his old truck as he upgraded and i was stoked as its the exact truck ive been chasing for a couple years now.
Anyway shes definitely not perfect ive had to do rocker covers, rear main, harmonic balancer, timing kit, etc.
When i got the truck i noticed oil in the top of the radiator and a lot of oil in the overflow bottle. The truck had the bottom end reco less than 70000ks ago and it was suspected that the head was fine and the top end was not needed to be redone.
He says the oil is due to something to do with the oil cooler.
Can anyone shed some light? Anyone had this problem too?
I hope its not the head gasket or head for that matter but any advice/info would be appreciated.

Yep, most probably oil cooler, or a leak in the head gasket between the oil and water galleries.

The reason why the oil is getting into the coolant is because the oil is under greater pressure (around 50psi) compared to the coolant (14psi), so it just finds the weakest link and is forced through.

Oil cooler - Basically this cools the oil via a heat exchanger with the engine coolant, usually located where the oil filter mount is. This may have a slight leak internally, so you wouldn't notice any oil just from looking at it.

This is easy enough to replace though, so I'd start with that. once you pull it out, you might immediately see the issue, or it may only prove itself with some pressure going through it. You could pressure test it by blocking the oil outlet and pressurising it with compressed air.

Cheers for the quick reply mate.
Would it be the gasket for the oil cooler or the oil cooler itself?
Would it be better just to replace the whole thing, flush the cooling system and then see how it goes?
And also where could i get a replacement?
Cheers in advance.
Holmesy

Yep, most probably oil cooler, or a leak in the head gasket between the oil and water galleries.

The reason why the oil is getting into the coolant is because the oil is under greater pressure (around 50psi) compared to the coolant (14psi), so it just finds the weakest link and is forced through.

Oil cooler - Basically this cools the oil via a heat exchanger with the engine coolant, usually located where the oil filter mount is. This may have a slight leak internally, so you wouldn't notice any oil just from looking at it.

This is easy enough to replace though, so I'd start with that. once you pull it out, you might immediately see the issue, or it may only prove itself with some pressure going through it. You could pressure test it by blocking the oil outlet and pressurising it with compressed air.

Cheers for the quick reply mate.
Would it be the gasket for the oil cooler or the oil cooler itself?
Would it be better just to replace the whole thing, flush the cooling system and then see how it goes?
And also where could i get a replacement?
Cheers in advance.
Holmesy